US1963924A - Electric toaster - Google Patents

Description

J. E. SMITH' ELECTRIC ToAsTER June 1.9, 1934.

Filled March 5, 1932 l2 sheets-sneer 1 gamma www n Mib/W1 June 19, 1934.v .L E; SMITH 1,963,924

ELECTRIC TOASTER Filed March 5, 1952 2 Sheets-Sheet 2 Figure 2 showingl Patented June 19, I 1934 ELECTRIC 'roAs'rER John E. Smith, Belleville, Ill. 'assignor to Knapp- Monarch Company, Bellevill tion of Missouri Application Marchi,v 1932, Serial No. 597,077

1o claims.

An object of my present invention isto provide i an electric toaster'with electric motor means for advancing bread therethrough and timing its period of passage through the toaster, the mechanism of the toaster being comparatively simple and inexpensive from a manufacturing standpoint.

A further object an electric motor operated means for advancing bread past the heating elements of the toaster,

with means for adjusting the speed of such advance so as to-obtain light, medium or brown toast as desired.

A further object is to provide ratchet means for advancing the bread, the ratchet means being operated by an electric motor and being manually adjustable to time the conveyance of the bread through the toaster, as desired.

A further Objectis to provide means for automatically reducing .the speed of the conveyor mechanism for the bread 'while the toaster is in cool condition and speeding up the-advance of the bread in proportion to the temperature rise of the toaster.

Still a further object is to provide the automatic means in the form ofa thermostatic mechanisrn which normally reduces the-speed of the 'bread conveyor, but upon becoming heated allows proportion to thethe speed thereof to increase in heat of the toaster as impartedby radiation and conduction to the thermostatic mechanism.-

Still another object is to provide conveyor mechanism movable longitudinally between heating elements arranged within a casing, the heating elements being closer to the discharge end of the casing. than to the intake end so-that a'warming compartment is provided lwithinthe casing for the bread before it actually comes into registry with the heating elements.

Y With these and other objects in` view my invention consists in the construction, arrangement and combination of the various parts of my electric toaster, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, in which:

Figure 1 is a perspective view of an electric toaster embodying. my invention.

Figure 2 is an enlarged sectional line 2-2 of Figure 1.

Figure 3 is a sectional view on the line 3-3 of a ratchet mechanism.

Figure 4 is a sectional view on the line 4-4 of Figure 2 showing a thermostatic mechanism.

is to provide a toaster having? lll., a ycorpora Figure 5 is a sectional view on the line 5-5 of Figure 3.

Figure 6 is a longitudinal sectional view through the toaster as taken on the line 6-6 of Figure 2.

lFigure 7 is a bottom plan view.

Figuresl 8 and 9 are b'ase 10 is preferably rial and is hollowed shown in Figure 2. On

diagrammatic adjustment mechanism of the toaster;

Figure 10 is a wiring diagram.

On the accompanying drawings, I reference numeral 10 to indicate a base.

formed of insulating mateout underneath, as clearly views of the and have used the The the base l0 is mounted a casing 12 having a top 14 and having intake and discharge openings 16 and 18, respectively, at its ends.

20 supported on plates Within the casing 12 I provide heating elements'l 22 of mica or the like,

which in turn are supported on metal plates 24. Grid Wires 26 are arranged between the heating elements 20 and are adapted to hold slices of bread from contact with the ordinary manner.

Referring to Figure 6, heating elements 20 are charge opening 18 than the heating elements in it will be noted that the located closer to the disthey are to the intake opening 16 and the purpose of this construction will hereinafter I provide a means for slices of bread A from the intake opening 16,

be set forth.

conveying or advancing past the heating elementst20 and out of the discharge opening 18. may be lof any desired Such `a bread support or conveyor movable form and on the drawings, I have shown a conveyor chain 27 for this purpose.

The chain 27 extends around a sprocket28 and around an idler roller 30, which` are mounted on shafts The sprocket 28 vis secured to 32 and 34, respectively.,

the shaft 32 and it will therefore be obvious that rotation of the shaft will cause movement of the conveyor chain 271.

The conveyor 'chain is provided with prongs, so as to effectively engage the lower edge of. the slices 'of bread for the purpose of advancing them. Intake and discharge platforms 36 and 38, respectively (see Figure 6) serve in conjunction with the chain 27 as guides for the bread as f it is advanced through the casing 12. view on the For rotating the sprocket 28 and accordingly imparting movement to I provide the conveyor chain 27,

an electric motor 40 and the following associatedmechanism. The motor 40 is provided with a worm rotation to a worm gear 42 on its shaft which imparts '44. The worm. gear 44 hub 28* lthe pin has a crank pin 46 arranged in a slot 48 at one end cfa link 50.

end of the link 50 is pivoted to a pin 52 carried by an arm 54. The armv54 straddles a ratchet wheel 56 which is secured to the of the sprocket wheel 28. Pivoted on 52 is a. pawl 58 for engaging the teeth of the ratchet wheel 56 and thereby rotating it whenever the link 50 is o scillated iny one direction.

A temperature responsive bar of bimetallic construction is indicated at 60. One end thereof is anchored to a pin 62 in any desired manner. The other end thereof indicated at 64 constitutes a thermostatic stop-for the pin 52. The position of the stop 64 can Abe adjusted by rotating a knob 66 and a. screw 68. The screw 68 is rotatable but non- V slidable relative to the casing l0 and is screw 40. In Figure 10,.the

threaded through the pin 62 or more 'specifically an enlarged head thereof as shown in Figure 5. It will therefore be obvious that rotation of the screw 68 will move the pin 62 longitudinally thereof and thus adjust the distance between the thermostatic stop 64 land the worm gear 44.

Besides the thermostatic stop 64, I provide a positive manual stop 70 which is one edge of'a lever 72.' The lever 72 is oscillatable on the shaft 32 and the pin 62 extends therethrough so that adjustment of the pin swings the arm 72. A spring 74 is provided on the arm 72 for constraining the pin 52 toward the thermostatic and manual stops 64 and 70 and thus returning the pawl 58 during each cycle of operation thereof.

The shafts 32 and 34 are provided with keys '76 to prevent their tive to the base 10 and to prevent longitudinal movement of the parts- 28a .and 72 relative to the shaft 32. In connection with the knob 66 and the threaded shaft 68, I provide a pinion 78 meshingbwith a gear sector 80. The gear sector 80 is connected with a pointer 82 whereby the adjustment of the pin 62 is indicated and suitable .indicating characters can be marked on the base 10 for light, medium and brown toast, for instance.A

The base 10 is provided with slots 84 and 86 for the sprocket 28 and the roller 30, respectively. Above the base 10, a supporting plate 88 is provided for the upper stretch of the conveyor chain 27., The shaft 32 is provided with a knob 90 ywhereby the conveyor chain 27 may be manually operated independent of the operation thereof as, caused by energization of the motor 40. On the base 10, I provide a switch 92 for switching on the heating elements 20 and the motor circuit is shown. It will be obvious that the heating elements andthe vmotor being controlled by the one switch are energized and denergized simultaneously.

To prevent reverse rotation of the sprocket wheel 28 when the pawl 58 is moved toward the left in Figure 3, I provide a friction spring 28b (see Figures 2 and 7).

- operation In the operation of my electric toaster, the switch 92 is moved to closed position whereupon the heating elements .20 will start to heat and the conveyor chain 27 will start moving because of the motor 40 being energized. With the knob 66 adjusted as shown in Figure 8, the link 50 will travel the distance indicated at a each revolution This distance is slight so be oscillated very far and 58 will not `advance the of the worm gear 44. that the arm 54 will not consequently the,pa wl longitudinal movement rela-- cated by the dimension form 38 and the conveyor chain 27 until it overbalances. It will then drop out of the toaster.

Since the distance a (see Figure 8) is quite small, it will be obvious that the bread will be advanced slowly. However, as the heating elements 20 become hotter and radiate their heat to the toaster and through the opening 84, the thermostatic element 60 will gradually warp to the dotted line position of Figure 8, thus lengthening the stroke, as indicated at b.

The chain 27, the sprocket 28, the hub 28a, the arm 72 and the Apin 62 will also serve to conduct heat to the element 60 to cause its warping to the dotted line position. When it does reach the dotted line position, then the edge 70 of the arm 72 will act as a positive stop so as to predetermine the maximum travel of the link 50 and accordingly the maximum speed of the chain 27 for the adjustment illustrated. Thereafter, the element 60 can warpl still farther without affecting the positive adjustment.

When the parts are adjusted as in Figure 9, however, the initial travel of the chain 27 is faster because the dimension a' is greater. After the thermostatic element 60, however, has'warped to the dotted line position shown in this ligure, the travel of the link 50 is stillgreater, it being indibf. With this adjustment, the chain travels faster during a given period of time and consequently the bread is not in the toaster as long and is not as brown as with the adjustment shown in Figure 8.

By comparing Figure 8 with Figure 9, it will be noted that the adjustment of the thermostatic stop 64 is in different proportion than the adjustment of the edge 70 of the lever 72. This is in order to keep the dimensions a and b somewhat in proportion with the dimensions a and b' so that at all positions of adjustmentr the comparative toasting of the bread will be the same when the toaster is fully heated as when it is just starting to heat.

The proportional difference just referred to is secured by the 4therrnostatic stop 64 being moved the same distance as the pin 62 when it is adjusted by reason of the stop 64 being secured thereto and the pin 62 being held non-rotatable by, and relative to the shaft 68, but the stop edge 70 ofthe lever 72 traveling farther because of being a greater distance from the axis of the shaft 32 than the pin 62, which is pivoted to the lever.

-Some changes may be made in the construction and arrangement of the parts of my device withoutfdeparting from the real spirit and purmay pawl means for imparting movement to said bread support to cause conveyance of bread past said heating element at a predetermined speed by the pawl picking up a vpredetermined number of ratchet teeth each cycle of operation and means responsive to temperature conditions of the toaster to decrease the number of ratchet teeth picked up by said pawl each cycle of operation until said toaster is thoroughly heated whereupon said predetermined number` are picked up.

2. In a bread toaster, a heating element, a bread support normally thereadjacent and movableto a position spaced relative thereto to terminate the toasting operation on bread carried thereby, timing means for so moving said bread support and including a ratchet and a pawl adapted to pick up a variable number of the teeth on said ratchet when said pawl operates through one cycle and thermal responsive means to adjust the number so picked up.

3. In a bread toaster, a heating element, a bread support normally thereadjacent and movable to a position spaced relative thereto to terminate the toasting'operation on bread carried thereby, timing means for so moving said bread support and adapted to pick up-a variable number of the teeth on said ratchet when said pawl operates through one cycle, manual means for adjusting the number of teeth so picked up and thermal responsive means for automatically decreasing said number till the toaster has heated up.

4. In a bread toaster, a heating element, a

bread support normally thereadjacent and mov- Iable to a position spaced relative thereto to terminate the toasting operation on. bread carried thereby, timing means for so moving said bread support and including a ratchet and a pawl adapted to pick up on said ratchet when said pawl operates through one cycle, thermal responsive means for automatically decreasing the number of teeth so picked up until said toaster heats up and manual means to adjust such number and also the position of said thermal responsive means.

5. In a bread toaster, a heating element, a bread support normally thereadjacentr and movable to a position spaced relative thereto to ter-v minate the toasting operation on bread carried thereby, timing means for so moving said bread support and including a ratchet and a pawl adapted to pick up a variable number of the teeth on said ratchet when said pawl-operates through one cycle, thermal responsive means for automatically decreasing the number of teeth so picked up until said toaster heats up and manual means to adjust such number and also the position of said thermal responsive means but in less degree.

6. In a device of the class described, an actuof ratchet teeth including a ratchet and a pawla variable number of the teethating elementl and means to adjust the stroke thereof comprising a manually adjustable stop and-a therma1 responsive element, said thermal responsive element being effective as a stop till a predetermined degree of heat is attained by said device and the manuallyl adjustable stop then being effective.

'7. Ina device of the class described, an actuating element and means to adjust the stroke thereof comprising a manually adjustablestop and a thermal responsive element, said thermal responsive element being eilective as a stop till a predetermined degree of heat is attained by said device and the manually adjustable stop then l'being effective,. said manually adjustable stop being associated with the thermal responsive element to adjust it when the manually adjustable stop is adjusted;

8. In a device of the class described, an actuating element and means to adjust the stroke thereof comprising a manually` adjustable stop and a thermal responsive element, said thermal responsive element being effective as a stop till a predetermined degree of heat is attained by said device and the manually adjustable stop then being effective, said manually adjustable stop being associated with the thermal responsive element to adjust it when the manually adjustable stop is adjusted, the degree of adjustment of the thermal responsive element being less than the degree of adjustment of the manually adjustable stop.

9. A device of the class described comprising an actuating element and means to adjust the stroke thereof comprising a manually adjustable stop lever and a thermal responsive element, 4said thermal responsive element being effective as a' stop till a predetermined degree of heat is attained by said device and the manually adjustable stop lever then being effective, the manually adjustable stop lever being associated at a point closer to its axis of movement than the stop portion thereof with said thermal responsive element to adjust it when themanually adjustable stop lever is adjusted.

10. In'a device of theclass described, an actuating element and means to adjust the stroke thereof comprising a pivoted lever having a stop portion of said actuating element than the stop portion of said lever.

JOHN E. SMITH.

actuating element, a stud pivoted to the lever between said stop portion and the'

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